A reference signal generator for generating an output reference signal
having a target duty cycle. The reference signal generator comprises a
sawtooth generator for receiving an input reference signal having a
reference frequency and generating a sawtooth waveform having the
reference frequency. Comparison circuitry compares the sawtooth waveform
to a reference voltage and generates the output reference signal. The
output reference signal is Logic 1 when the sawtooth waveform is greater
than the reference voltage and is Logic 0 when the sawtooth waveform is
less than the reference voltage. Feedback circuitry determines a duty
cycle of the output reference signal by comparing a first time period
when the output reference signal is Logic 1 to a second time period when
the output reference signal is Logic 0. The feedback circuitry adjusts a
value of the reference voltage to cause the output reference signal to
achieve the target duty cycle.